I. What are non-metallic minerals
Non-metallic minerals refer to certain non-metallic elements that are economically useful, or mineral resources that can directly utilize certain chemical, physical or technological properties of minerals or rocks. China is rich in non-metallic mineral resources, with a wide variety and extensive distribution. A total of 95 types of non-metallic minerals have been discovered across the country.
Ii. What are the non-metallic minerals
Metallurgical auxiliary material minerals: such as magnesite, refractory clay, silica, dolomite, fluorite, etc.
2. Special non-metallic minerals: such as diamond, quartz, Iceland sinite, mica, tourmaline, etc.
3. Non-metallic minerals in the chemical industry: such as phosphorus, sulfur, potassium salts, magnesium salts, natural soda, mirabilite, ground wax, etc.
4. Building materials: such as basalt, granite, marble, gypsum, etc.
5. Ceramic and glass raw materials: such as kaolin, plastic clay, quartz sand, feldspar, etc.
6. Non-metallic minerals for arts and crafts and gemstones: such as ruby, sapphire, purple ivory stone, jade, grossular garnet, phoenix brain stone, agate, turquoise, opal, chalcedony, amethyst, smoky quartz, hair quartz, malachite, tourmaline, epidote, tremolite, Iceland sinite, inkstone, etc.
7. Other materials: such as vermiculite, pumice, diatomite, asbestos, graphite, talc, etc.
Iii. Causes of the Formation of Non-metallic Minerals
The causes of non-metallic minerals are diverse, but magmatic, metamorphic, sedimentary and weathered types are the most important. In addition, submarine jet flow is also significant. For instance, pyrite mainly belongs to this type of cause.
Magmatic activity
The volcanic lava, volcanic ash and other materials formed by the upward intrusion of magma into rock masses or after erupting to the surface can all form non-metallic mineral resources. Intrusive rock masses such as gray feldspar and granite can all be used as high-quality building materials. The well-known "General's Mouth" granite floor in China and the "Indian Red" granite produced in India are both potassium feldspar granites. Pumice and perlite formed by ejection to the surface are both indispensable industrial raw materials, and volcanic ash can also be used as agricultural fertilizer. There are also two special types of igneous rocks, namely kimberlite and potassium-magnesium lamprophytes, which contain relatively abundant diamonds inside. Most of the diamonds in the world are produced in these two kinds of rocks.
2. Metamorphism
When rocks are basically in a solid state, they undergo changes in mineral composition, chemical composition, rock structure and texture under the influence of temperature, pressure and chemically active fluids, thus forming non-metallic deposits. Commonly used materials in industry and daily life include graphite, asbestos, kyanite, andalusite, talc, mica, etc. The Nanshu Graphite Mine in Shandong Province, as well as the rutile and asbestos mines in Henan and Shaanxi, are all well-known domestic production areas.
3. Sedimentation
Rocks and ore bodies exposed on the surface, under the long-term influence of the atmosphere and water flow, undergo erosion, transportation, differentiation and deposition, eventually forming non-metallic mineral resources. They can also directly form non-metallic mineral layers through chemical precipitation and biochemical processes. It is mainly divided into three categories: (1) Placer deposits, which are mainly formed by the separation of water flow, glaciers, wind force, etc. Rare minerals such as diamond, rutile, zircon and monazite can all be enriched and formed through this mechanical differentiation process. (2) Biochemical processes, such as phosphate rock being directly formed by the accumulation of bird droppings, diatomite rock being formed by the accumulation of diatom remains, and there are also sulfur minerals related to volcanic eruptions, etc. (3) Salt mines formed by chemical reactions, such as table salt indispensable to humans, gypsum and saltpeter used in industry, potassium salts used in agriculture, and laxative salts used in medicine, are all caused by chemical crystallization and precipitation during the evaporation process of salt lakes.
4. Weathering
Rocks or ore bodies exposed on the surface, after a long process of rainfall, light exposure, oxidation and biological action, change the chemical composition and mineral appearance of the surface substances, thus forming non-metallic materials that can be utilized. The clay minerals indispensable in daily life and industry are mostly formed by this reason. For instance, kaolin and bentonite are all formed by the weathering of rocks. It is precisely this process that provides raw materials for humans to make ceramics, cosmetics, environmental treatment products, medicines, paints and other substances. Looking at it from a broader perspective, even the soil on which all living things depend for survival is a non-metallic resource formed by weathering.